1st Orthopedic Department, C.T.O. Hospital, Via Bignami 1, 20100, Milan, Italy.
Int Orthop. 2011 Jan;35(1):19-24. doi: 10.1007/s00264-009-0903-1. Epub 2009 Nov 11.
Leg length discrepancy following total hip replacement (THR) can contribute to poor hip function. Abnormal gait, pain, neurological disturbance and patient dissatisfaction have all been described as a result of leg length inequality after THR. The purpose of this study was to determine whether the use of computer navigation in THR can improve limb length restoration and early clinical outcomes. We performed a matched-pair study comparing 48 computer-assisted THR with 48 THRs performed using a traditional freehand alignment method. The same implant with a straight non-modular femoral stem was used in all cases. The navigation system used allowed the surgeon to monitor both acetabular cup placement and all the phases of femoral stem implantation including rasping. Patients were matched for age, sex, arthritis level, pre-operative diagnosis and pre-operative leg length discrepancy. At a minimum follow-up of six months, limb length discrepancy was measured using digital radiographs and a standardised protocol. The number of patients with a residual discrepancy of 10 mm or more and/or a post-operative over-lengthening were measured. The clinical outcome was evaluated using both the Harris Hip Score and the normalised Western Ontario and McMaster Universities (WOMAC) Arthritis Index. Restoration of limb length was significantly better in the computer-assisted THR group. The number of patients with a residual limb length discrepancy greater than 10 mm and/or a post-operative over-lengthening was significantly lower. No significant difference in the Harris Hip Score or normalised WOMAC Arthritis Index was seen between the two groups. The surgical time was significantly longer in the computer-assisted THR group. No post-operative dislocations were seen.
全髋关节置换术后的肢体长度差异可导致髋关节功能不良。异常步态、疼痛、神经功能障碍和患者不满都被描述为全髋关节置换术后肢体长度不等的结果。本研究旨在确定在全髋关节置换术中使用计算机导航是否可以改善肢体长度的恢复和早期临床结果。我们进行了一项配对研究，比较了 48 例计算机辅助全髋关节置换术和 48 例采用传统徒手定位方法的全髋关节置换术。所有病例均使用直型非模块化股骨柄的同种假体。所使用的导航系统允许外科医生监测髋臼杯的放置和股骨柄植入的所有阶段，包括锉削。患者按年龄、性别、关节炎程度、术前诊断和术前肢体长度差异进行匹配。在至少 6 个月的随访时，使用数字 X 线片和标准化方案测量肢体长度差异。测量有 10mm 或更多残余差异和/或术后过长的患者数量。使用 Harris 髋关节评分和标准化的安大略西部大学和麦克马斯特大学（WOMAC）关节炎指数评估临床结果。计算机辅助全髋关节置换组肢体长度的恢复明显更好。有 10mm 或更多残余肢体长度差异和/或术后过长的患者数量明显减少。两组之间的 Harris 髋关节评分或标准化 WOMAC 关节炎指数无显著差异。计算机辅助全髋关节置换组的手术时间明显更长。无术后脱位。
